only way it would be the boost olive is if the thing has been removed. Reasons why it would be removed would be;
replaced split hose and didnt notice it
removed to use manual boost controller.
If you pinch along the hose coming from the turbo actuator you should be able to feel it. It could be that the ECU has gone into limp mode due to any number of reasons. Without looking at it by a decent mechanic that knows subaru you will be chasing your tail asking for an online diagnosis.